Mailing tube



y 31, 1956 c. A. ABRAHAMSON 2,

MAILING TUBE Filed June 7. 1954 FIGB.

3nventovr CLARK 'A. A8 RAHAM SON Clttorneg United States Patent MAILING TUBE Clark A. Abrahamson, St. Paul, Minn., assignor to Quality Park Box Company Incorporated, St. Paul, Minn., a corporation of Minnesota Application June 7, 1954, Serial No. 434,973

1 Claim. (Cl. 229-93) My invention relates to an improvement in a mailing tube for rolled sheet material and more particularly to the formation of the end of the tube whereby the turnedin end of the same may be easily ruptured and partly opened to allow easy removal of the rolled sheet material from the tube.

Present day mailing tubes for protective shipping of rolled sheet material such as calendars are generally formed of fused ribbon-like layers of spirally wound cardboard in tubular form with the ends rolled or turned in by machine. The turning or rolling in of the ends of the tube forms a firm shoulder on each end inside'the tube and prevents the rolled sheet material from coming out of the tube. It is virtually impossible to remove the sheet material without in some way getting rid of the turned-in shoulder. It is difiicult to pull out the turnedin shoulder, and in lieu of getting rid of the shoulder it is difiicult to break the tube without damaging the sheet material inside. Various devices have been tried to remedy the situation but have required additional means and have added too much to the cost of the mailing tube.

It is a primary feature of my invention to form a slit or saw cut of a predetermined depth in a portion of the end edge of the tube and the turned-in portion which allows the user to tear and lift up a portion of the end of the tube to expose the end of the rolled sheet material for easy removal from the tube. The slit or cut may be easily and efiiciently made by means of a circular cutting disc to a depth of approximately half of the thickness of the wall of the tube and the turned-under portion which leaves the wall and turned-under shoulder portion of suflicient strength to resist rupture in the mail handling of the tube.

As a portion of the end of the tube is grasped adjacent the slit and pulled upwardly, the tube generally tears in the direction of or along the spiral formation of the cardboard layers, thus quickly opening the end of the tube and exposing the portion of the end of the rolled sheet material.

It is a further feature to form the slit or cut arcuated in form so that a portion of the wall of the tube and the shoulder are simultaneously each cut the proper amount in a simple single cut.

The mailer tubes herein defined are primarily used for mailing calendars and similar sheet articles which when rolled up may be easily inserted into the mailing tube. Such articles usually expand slightly after entering the tube and therefore it is important that the retaining shoulder be formed in the tube on either end thereof.

These mailer tubes are usually made on an automatic winding machine which winds the several layers of cardboard, one upon the other, with the seam of one layer being out of line with the other layer and said seams extending spirally throughout the length of the tube. This construction of mailing tube is strong, light weight, and forms a mailing tube having the necessary rigidity and strength to fully protect the contents of the tube in passing through the mails.

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The tearing slit need only be formed at one end of the tube. Indicia can be printed on the tube adjacent the slit to instruct the recipient thereof where to engage the edge of the tube so that it can be readily torn open when desired. In tearing the tube open, the retaining shoulder, which has been formed by tearing in the end of the tube, is torn away permitting the contents of the tube to slide out freely without injuring the same.

In forming this mailing tube, which is ordinarily used for calendars and the like, it is the practice to cut the tubes ofi in predetermined lengths and the ends are rolled in to provide an annular shoulder which retains the rolled up calendar within the tube. The calendar is rolled slightly smaller before it is inserted into the mailing tube and then as it completely enters the tube the rolled calendar expands to fit the inside of the tube, whereupon the inturned ends of the tube act as retaining shoulders to hold the calendar within the mailing tube.

Therefore, to remove the calendar from the mailing tube without injuring the edges of the same it is necessary to remove the turned-in shoulders of the tube and this I accomplish in a simple manner by cutting a slit in the end of the tube which penetrates the inturned end of the tube. It is important that this cut in the end of the tube is not too deep, otherwise the tube would be weakened and will not protect the contents thereof and will be inclined to tear away in the course of mailing the same.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings, showing by way of example a preferred embodiment of the inventive idea wherein like numerals are employed to designate like parts throughout.

In the drawings forming part of the application;

Figure l is a perspective view of a mailing tube, partly broken away, showing the turned-in end portion and the cut formed therein.

Figure 2 is a perspective view of the mailing tube with a portion of the end of the same partly torn away.

Figure 3 is a longitudinal side view of the disclosure shown in Figure 2.

Figure 4 is a longitudinal sectional view of a portion of the end of the tube and the sheet material positioned therein.

Referring to the drawings in detail, my improved mailing tube A is generally formed of spirally wound ribbonlike layers of cardboard such as 11, thereby producing the spirally formed joints such as 12. The tubes are made of several layers of staggered spirally wound ribbon-like sheets of cardboard with the under sheets underlying the spiral joints immediately above. As a result the spiral joints of the cardboard material are staggered with respect to the various layers of cardboard thereby allowing tearing of the tube at any point near or at one of the spiral cardboard joints. Spiral joints, such as 12, also appear on the inside of the tube such as the underlying joint 13 due to the above construction.

The end of the tube A is formed with the rolled-in annular portion 14 which results in the inner shoulder 15. The shoulder 15 prevents the rolled calendar B from coming out of the tube A. Both ends of the tube are formed with the portion 14. The rolled-in annular portion 14 is pressed firmly into formation and as a result is removed only with extreme difficulty. To meet this difficulty of opening one end of the tube A for removal of the sheet material B, I provide the arcuated slit 16 which may be formed by a thin circular cutter or saw disc forced into a portion of the wall of the tube A and also into a portion of the turned-in portion 14 particularly illustrated in Figure 4 of the drawings. With the cut 16- formed arcuate in shape the same neatly extends into a portion of the wall of the tube A and also into a portion of the shoulder 14. The cut 16, of course, may be formed other than arcuated.

With the approximate depth of the cut 16, as shown in Figure 4, the end turned-in portion 14, adjacent the cut 16, may be grasped-and torn. upwardly to the position shown in Figures 2 and 3. As the end of the tube A is forced into the position shown in Figures 2 and 3, the tearing of the Wall of the tube begins at the point 37 and continues along the line 18 Which is generally at or adjacent one of the spiral joints such as 12 or 13.

Thus, with the aid of the cut 16, the end of the tube A is easily opened progressively away from the end of the tube and towards the center of the tube due tothe spiral construction. The entire tube can be torn apart in this manner, but generally if the tube is torn to the extent shown in Figure l the sheet material B may be easily removed. With my improvement the firm annular turned-in portion 14 and the accompanying shoulder 15 are easily and effectively gotten out of the way. With my improvement, nothing'is added tov the mailing tube A for opening the end of the same except that the slot 16 is provided. I thus provide a simple and economical improvement for a mailing tube to allow a foolproof reliable opening means which is not disrupted during the handling of mail or express.

The slot 16 is formed on the portion 14 substantially on the radius of the transverse section of the tube A and extends on the tube parallel to the longitudinal axis thereof.

Adjacent the slot 16, I imprint the tube A with the ind-icia 1-9- To Open Tear Here. This indicia 19 indicates to the recipient the place where the end of the tube can be engaged and torn open.

The invention is not to be understood as restricted to the details set forth since these may be modified within the scope of the appended claim without departing from the spirit and scope of the invention.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

A mailing tube formed with a cylindrical body, open ends formed on said body, annular shoulders formed in the ends of said tube by rolling the end of the tube inwardly, to provide annular shoulders in each end of the tube for retaining a calendar or the like therein for mailing and an axially disposed slit cut into a portion of the in-turned end of said body and a portion of said body to a predetermined depth and without cutting completely' through the in-turned shoulder endof the tube, said slit providing an easy tearing means to permit the shoulder formed by the in-turned end of the tube and a portion of the cylindrical body to be torn away, whereupon the contents of the tube can be readily removed.

References Cited in the file of this patent UNITED STATES PATENTS 

